Cooling of engines in aircraft



i F. B. HALFORD' EFAL I 2,405,422

I COOLING OF ENGINES IN AIRCRAFT I s Sheets-Sheet 1 Filed Feb. 14 1945 In ventols 5.3 {ha/=0 4L fawn/715: V orneys 6- v F. s. HALFORD' ETAL F 2,405,422

' COOLING 0F ENGINES IN AIRCRAFT Filed Feb. 14,1945 3 Sheets-Sheet 2 F. B. HALFORD EI'AL 2,405,422 COOLING QF'ENGINES IN AIRCRAFT Filed Feb. 14, i945 s Sheets-Sheet 3 Patented Aug. 6, 1946 COOLING ENGINES AIRCRAFT Frank Bernard Halford, Edgware, and Cecil Louis Cowdrey, Hitchin, England, assignors to D. Napier & Son Limited, London, England, a company of Great Britain Application February 14, 1945, Serial No. 577,914 In Great Britain November 15, 1943 4 Claims.

This invention relates to the cooling of engines in aircraft and has for its object to efiect certain improvements in the construction associated with an annular passage in which is situated a radiator arranged as described in the specification of application for United States of America Letters Patent Serial No. 524,642 in the name of one of the present applicants and another. In that case there is an annular passage within the cowling having the opening. into it behind the airscrew and around the fore part of the engine casing. In this passage is a radiator having a generally annular formation, and a fan which rotates about the airscrew axis is disposed at the opening into this passage behind the airscrew. This fan delivers air which passes through the passage and the radiator therein.

According to this invention the air which has passed through the radiator issues from the passage through an annular opening in the cowling and an annular shutter or gill movable in the direction of the engine axis serves to vary-the extent of this outflow opening and thus control the air flow through the radiator. The annular shutter or gill is moved by hydraulic or electric means which may comprise several hydraulic cylinder and piston assemblies or electrically operated devices spaced apart circumferentially and all operative on the shutter to move it over or into or withdraw it from the annular opening through which the air issues. The complete annular shutter may be thus movable as a whole, or it may be made in segments each of suitable length in the circumferential direction and movable separately or in groups as required.

The annular passage in which is the radiator may have the opening through which the air enters and where the fan is situated disposed so that the air flowing to the opening passes over the exterior of the spinner. In an alternative arrangement where there is a hollow spinner there is provided an annular passage through the spinner which leads past the propeller blades to the fan in the entry to the annular passage containing the radiator.

The accompanying drawings illustrate by way of example constructions which may be employed in carrying the invention into practice. In these drawings,

Figure 1 is a somewhat diagrammatic longitudinal sectional elevation showing one construction.

Figure 2 is a similar view in which is shown another arrangement of the annular air passage 2 the forward part of whichis carried through the spinner and past the propeller blades.

Figure 3 is a perspective view'of a sliding gill or shutter with apparatus for operating it by electric means.

Referring to Figure 1,, an annular radiator A of suitable construction is disposed in the annular air passage B which runs through 'the cowling, a fan C being placed at the entry to the passage behind the blades D of the propeller. Thi fan rotates in the opposite direction-to the propeller. At the rear end B of the air passage there is mounted the annular gill or shutter which comprises a part E which is thicker, considered in the radial direction, and a thinner rearward part E The forward part E is externally of streamline shape and adapted to be moved forwardly into the outlet 13 and thereby control the flow of air through the passage B and the radiator A. As shown the movable gill EE is made hollow and on its inner side it is formed with a shoulder E with a substantially flat radial face which is engaged by several hydraulic cylinder and piston assemblies F. These cylinder and piston assemblies of which only one is shown in the drawings, are mounted in an annular flange G within the-cowling H the cylinder and piston assemblies being equally spaced apart circumferentially and with their axes parallel to the propeller axis. The thinner part E of the gill lies outside and moves over the part of the cowling around the cylinder and piston assemblies. The thickness of the fore part E of the gill is determined by the radial width of the outlet B from the air passage.

The streamlining of the part E of the gill ensures the easy outflow of the air whether the opening is constricted by movement into it of the gill, or whether this has been moved into its retracted position. The surface of this part of the gill constitutes in effect the end portion of the inner wall of the part B of the air passage beyond or to the rear of the radiator A. The inner surface of the fore part E of the gill is cylindrical as at E so that when the gill is moved forward to constrict the air passage this part of the gill will lie over the adjacent part of the end of the radiator and thus obstruct the air flow through that part of the radiator.

In the alternative arrangement shown in Figure 2 the spinner J has formed therein an annular passage K through which the air can flow past the propeller blades D to the fan C and then into the forward end of the annular passage B in which is situated the radiator A. In other respeots the air passage is as described and shown in Figure 1 and the air flow through it is controlled by an annular gill E which is moved in the .direction of the propeller axis by a series of electrically actuated screw jacks F The gill a-s showm diagrammatically by itself in Figurea 3, is-: arranged so thatthe; necessary movement will be imparted to it by electric means. Screw jacks F as also seen in Figure 2; are spaced apart circumferentially and act on the rear face E of the gill E. This face maybe formed as a shoulder similar to the. shoulder-E as seen in Figures 1 and 2. An electric. motonh suitably positioned actuates. the several: screw jacks simultaneously through flexible drives M and M and gearing arranged in, the casings N.

The formation and arrangement of the annular passage B and the radiator A therein are preferably as generally' described in the specification of the'prior patent application mentioned above. That is to say the passage runs rearwards over the fore part of the: engine casingin a general-ly'conical direction the annular entry or mouth of the passage being of less diameter-than the outflow end and having the fan C- in front of this mouth. The radiator of which the structure may vary ispreferably designed to efiect cooling of the engine lubricant as well as the liquid used for cooling the engine. The fan conveniently rotates in a. direction opposite to that in which rotates the airscrew. In the earlier arrangement theair issuing; from the rear end of the; passage was led; overthe engine casing and exhaust pipes to an annular or; other opening at the. rear of: the engine. the. outflow being controlled by one or more valves.

The present improvement with respect to the air outflow provides a better control for'the airflow through the passageand'radiator and is also preferable from the aerodynamic aspect.

The manner in which the. sliding; Shutter or gill is mounted so as to ensure ease of. movement and obviate risk. of sticking may vary. The fore part is conveniently guided by an annular rib O at. the inner. side. of the exit. B from the passage, as. shown. in. Figure 1,. and. the inner surface E of the annular gill. rests and: slides on. this rib.

Towardsits rear end the shutter may be suitably guided where its thinner rear: part 13 liesover the-part of thecowling.

What we claim as our invention and desire to secure by Letters Patent is:

1. In an aircraft the combination of an engine casing, a cowling extending rearwards from the fore part of the engine and outside its casing, an airscrew, an annular passage running rearwards between the said cowling and the said engine casing from an inlet opening behind the airscrew to an annular outlet opening in the cowling. a. radiator having a generally annular formation disposed in this passage, a fan rotatable aboutv the airscrew axis in a direction contra to; that of the airscrew and situated between the: airscrew and the inlet opening into the said annular passage into which air is delivered by the-fanto flow. through the radiator, an annular shutter mounted adjacent to and at the rear of the said annular outlet opening in the cowlingthrough which the air flows after passing through the radiator, and means for moving this shutter; the, direction. of the; airscrew axis so as to. vary the dimensions, of the; said: outflow opening; and thereby control; the air-flow through the radiator.

2. An aircraft having in combination the; parts asset out in claim 1 in which. the said: shutter is. formed: hollow with. externally a streamlined contour and the forepart which lies next to. the said, annular outlet: opening thicker inv the radial direction than the rear: part, this rear part: lying and being movable: over the adjacent". part: of the cowling while the thicker fore. part overhang and can; bev moved into the said annular outlet opening;

3. An aircraft having-incnmbination the; parts as. set out in claim 1'. in. which the airscrew is provided withsa. spinner having: an annular. passage running through it: to the. said fan behind the airscrew, this passage leading to the inlet opening of the said annular passageway through the cowling which lies. the. radiator;

aircraft having in combination the parts as set out in claim 1 and a plurality of' poweroperated jacks by which movement is imparted to the said annular shuttter, these jacks being mounted within the cowlin'g and to the rearward of the annular shutter to which they are respectively connected the jacksv being spaced apart circumferentially with their axes substantially parallel to the airscrew axis.

FRANK BERNARD HALFORII CECIL; LOUIS COWDREY. 

